Their annual energy for the post retrofit monitoring period was 8,136 kWh. Their 110-year-old home was previously insulated and had a relatively efficient heating system. As part of the retrofit they substantially increased the finished floor area and still achieved a 61% reduction in energy use from their baseline.

Attached is a spreadsheet with data from our twenty completed projects.

Interesting numbers, ranges, means, and comparisons! I welcome your observations. What is most interesting from the attached spreadsheet? Please provide suggestions for charts and graphs to tell the story of the 1000 Home Challenge projects to date.

Replies to This Discussion

As stated above the average for the first 20 projects is 6.9 KBtu/ft2; national average for single family homes is 44.8 KBtu/ft2.

This chart also provides an indication of project cost (H - High, M - Medium, and L - Low). You do not necessarily need to do a complete deep energy retrofit of a home to achieve a deep energy reduction in energy costs. However, as with the Sloan/von Gouler project, the value proposition of a deep energy retrofit goes way beyond lower energy costs.

Thanks Linda. What I found interesting about the spreadsheet data you've shared is that it shows that achieving DER is possible with any age of house with or without PV with varying amount of investment. This means a homeowner can be creative in their path towards DER as long as there is commitment and focus. Good news!

We are THC candidate and have few more months to billing data to collect to complete the first year of occupancy. The monthly average on our our energy bill has been 279 kWh/month for the past 8 months. We'll see how this passive house performs in the winter months.

What is your gas usage to date? Is the 279 kWh just your electric use, or does it reflect gas and electricity? As I recall, you use electricity for the clothes dryer and cooking, and gas for water and space heating, correct?

I have really enjoyed your blog. Please add the link to it for folks who may want more info about your project.

Hi Linda, the 279 kWh/month average includes both gas and electricity. We've been having a bit of a cold snap here and the sun isn't shining as much, so our backup gas boiler is kicking on every day. We moved into the house in mid-March so we have a few more months of data gathering and I'm curious how much gas we'll end up using.

I just spent some time on Chie's midorihaus blog, describing the progress of engaging in a deep energy reduction project of their home. Lots of great, useful info! Check it out and I think you will agree.

I must say, I'm not a fan of EUI as an energy performance metric (for residential buildings, at least), because it rewards larger houses, and doesn't penalize larger aggregate absolute energy consumption. Energy consumption per house or per occupant are better metrics, in my mind.

I would also like to see a greater differentiation made between energy consumption and on-site energy generation. Though from a carbon emissions standpoint, grid (fossil fuel derived) energy consumption reduction through renewable on-site generation is equivalent to reduction through conservation, so I see the logic. But still. Not using energy, and using energy generated on-site are not the same thing.

Maybe one thing to add to the spreadsheet or graphs could be the carbon emissions from the homes, along with that of the typical US home?

Thanks for all that you do. Great to see the THC Home Energy Pros page lively again!

I share your concerns about using EUI as a metric. Any metric that is based on square footage of living space favors bigger buildings and penalizes smaller buildings.

I envision that we need a constellation of metrics to tell the story of a home's or an initiative's energy performance. It was only recently that I worked the THC OPTION B allowance backwards to see what the range of EUI would be for different climates, house sizes, and occupancy.

OPTION B of the 1000 Home Challenge generates a threshold that balances a number of inputs, and only uses finished floor area in order to estimate shell surface area (five sides). Below is a graphs that I find interesting. Hopefully, as a result, the OPTION B allowance meets the objective of being difficult to achieve across the full range of North American housing stock - ideally not favoring warm climates, cold climates, big homes, small homes, old homes, new homes, energy hogs or energy misers, homes serviced by low carbon electricity, or homes serviced by hydro.

The Option B criteria themselves do an excellent (heroic, beautiful, gold-standard -- what other superlatives can I think of?) job at controlling for all the factors you cite, normalizing the difficulty for homes having different occupancies, behaviors, climate zones, heating types, etc. But then in the end to subvert all that innovative, clear thinking by comparing performance using EUI -- seems strange. I understand the rationale -- it's a commonly-cited and broadly-understood metric. But then again, hey, whatever it takes; if EUI motivates and engages people and is not used in the certification process itself (but only after the fact), I'm all for it.